Control units in a vehicle customarily have serial interfaces such as SPI, UART, LIN, CAN, PSI5, FlexRay, SENT, I2C, MSC (Micro Second Channel), Ethernet and others for connecting to or communicating with other control units, sensors, actuators or other peripheral devices. According to the related art, these serial interfaces are implemented with the aid of a VHDL code in a microcontroller of the control unit. In terms of hardware, depending on the interface, e.g., an interface-specific communication controller, including protocol controller, sample unit, memory unit and transceiver (transmitter/receiver) must be implemented for the implementation of a serial interface. A bus transceiver is not necessary with SENT and SPI, for example. Interface-specific hardware units (e.g., buffer with SPI, protocol controller with CAN) make such an implementation additionally complex and inflexible.
From WO-2006013212 A1, for example, the implementation of a FlexRay communication module for coupling a FlexRay communication link to a user assigned to the FlexRay communication module in a FlexRay network is discussed. A microcontroller having a typical configuration of serial interfaces is discussed, for example, in the document “16/32-Bit Architecture, XC2387C, XC2388C, 16/32-Bit Single-Chip Microcontroller with 32-Bit Performance, XC2000 Family/High Line, Data Sheet V1.3 2011-07” from Infineon.
The requirements in regard to the type and number of serial interfaces in different vehicle applications for a control unit or for a microcontroller of such a control unit vary greatly. For example, the requirement in one application may read: one SPI interface, two LIN interfaces, 5 CAN interfaces. In another more demanding application, further interfaces such as FlexRay or Ethernet may additionally be required, or a higher number of existing interfaces must be present. To address this, a microcontroller having a very large number of interfaces of different types may be used; however, this microcontroller would be over-engineered for a large number of applications, and thus too expensive. As an alternative, a specific microcontroller having exactly the desired number of each interface type may be implemented for each application; however, this is inconsistent with the desire for standardization and results in high implementation costs. Both approaches are additionally inflexible for still unknown future requirements. Overall, the interface-specific hardware implementation of the serial interfaces in a microcontroller for a vehicle control unit thus results in inflexible approaches, which are adaptable to different requirements only with complexity.